Function.prototype.jingeApply = function (thisArg,argArray = []) {
  // 保存调用的方法
  const fn = this
  // 将thisArg转为数组
  thisArg = (thisArg !== null || thisArg !== undefined) ? Object(thisArg) : window
  // 执行调用的方法，隐式绑定thisArg
  thisArg.fn = fn
  const result = thisArg.fn(...argArray)
  delete thisArg.fn
  // 将执行结果返回
  return result
}

function demo (num1,num2) {
  console.log('我是原函数',this);
  console.log(num1,num2);
  return num1 + num2
}

demo.jingeApply('abc',['1','2'])